/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: Admin
 * Date: 2022-05-11
 * Time: 16:50
 */
public class Main {
    public static void main(String[] args) {
        Stack stack = new Stack();
        stack.push(15);
        stack.push(20);
        stack.push(25);
        stack.push(30);

        int ret1 = stack.pop();
        System.out.println(ret1);


        System.out.println("========================");
        int ret5 =stack.peek();
        System.out.println(ret5);
        int ret6 = stack.pop();
        System.out.println(ret6);
    }
}
